484 MISC. PUBLICATION 42 3, U. S. DEPT. OF AGRICULTURE 



41. Astragalus palmeri A. Gray, Amer. Acad. Arts and Sci. Proc. 7: 



398. 1868. 



Phaca palmeri Rydb., North Amer. Fl. 24: 355. 1929. 



Graham County, at Camp Grant, 4,800 feet (Palmer in 1867, the 

 type collection), and San Carlos River (Mohr in 1873). Known only 

 from southeastern Arizona. 



42. Astragalus sabulonum A. Gray, Amer. Acad. Arts and Sci. Proc. 



13: 368. 1878. 



Phaca sabulonum Rydb., Torrey Bot. Club Bui. 40: 47. 1913. 



Coconino and Mohave Counties, along the Little Colorado and 

 Colorado Rivers, from Leupp and Lees Ferry to near the mouth of the 

 Virgin River, up to 4,500 feet, sometimes growing with Artemisia 

 tridentata, May. Northern Arizona and southern Nevada to south- 

 eastern California and Sonora. 



43. Astragalus humillimus A. Gray in T. S. Brandeg., Rpt. U. S. Geol. 



and Geog. Survey Ter. 2: 235. 1876. 



Phaca humillima Rydb., Torrey Bot. Club Bui. 32: 665. 1906. 



Grand Canyon, Coconino County, 7,000 feet, "apparently common 

 on sandy ledges" (M. E. Jones in 1903), April and May. Western 

 Wyoming, southwestern Colorado, and northern Arizona. 



Jones' specimens have flowers only, but correspond well with the 

 type of this species from Mesa Verde, Colorado, except that the 

 stipules are much more pubescent in the latter. 



44. Astragalus thurberi A. Grav, Amer. Acad. Arts and Sci. Mem. 



ser. 2, 5: 312. 1855. 



Phaca thurberi Kearney, N. Y. Acad. Sci. Trans. 14: 34. 1894. 



Cochise, Santa Cruz, and Pima Counties, 3,000 to 5,000 feet, com- 

 mon on dry rocky slopes and mesas, April and May. Western New 

 Mexico, southern Arizona, and Sonora. 



This species is definitely known to cause loco disease. It is recog- 

 nizable as a small plant with nearly globose, thin-walled pods. 



*45. Astragalus ampullarius S. Wats., Amer. Nat. 7: 300. 1873. 



Phaca ampullaria Rydb., Torrey Bot. Club Bui. 40: 47. 1913. 



Likely to be found in extreme northern Arizona, the type having 

 been collected at Kanab, Utah, a few miles north of the State line. 



46. Astragalus preussii A. Gray, Amer. Acad. Arts and Sci. Proc. 6: 

 222. 1864. 



Phaca preussii Rydb., Torrey Bot. Club Bui. 40: 47. 1913. 



Apache County to northern Mohave County, 3,300 to 6,000 feet, 

 June. Western Colorado to northern Arizona and southeastern 

 California. 



Most of the Arizona specimens belong to var. latus M. E. Jones 

 (var. arctus Sheldon, Jonesiella arcta Rydb.). This form, perhaps 

 specifically distinct, has the leaflets elliptic to narrowly obovate, 

 corolla whitish, and pods usually pronouncedly stipitate. In the 



